Reduced intergranular magnetic coupling in Pd/Co multilayers

The ideal magnetic switching mechanism for many types of data storage, including hard disk recording, is isolated domain coherent rotation. However, in typical Pd/Co multilayers with high coercivity, the dominant switching mechanism is domain wall motion, which causes noise in the readback signal. We have investigated the addition of-elements, such as carbon, into Pd/Co multilayers to reduce the coupling between adjacent magnetic domains. This reduction of magnetic coupling reduces the length scale over which incoherent switching occurs. Kelly-Hankel plots and the switching radius ratio have been used to compare interactions and domain sizes of oxidized and carbon segregated Pd/Co multilayers. Both oxidation and carbon segregation reduce the coupling between domains, but the multilayers nevertheless remain more strongly coupled than perpendicular alloy films. (C) 1996 American Institute of Physics.